Electrical properties of TiO2 thin films formed on self-assembled organic monolayers on silicon

Abstract

TiO 2 thin films were synthesized onto sulfonated self-assembled organic monolayers from Ti4+ aqueous solutions at low temperature (80 °C). The deposited TiO2 thin films were characterized using Rutherford backscattering spectroscopy and transmission electron microscopy. The electrical properties of the TiO2 films were measured using capacitance–voltage (C–V) and current–voltage techniques. From C–V measurements, the dielectric constants were calculated to be in the range of 24–57 for the as-deposited films and 67–97 for films annealed at 400 °C. For the as-deposited samples, the breakdown voltage was 2.7 MV/cm, the leakage current was 4.5×10−6 A/cm2, the resistivity was 1–1.5×109 Ω cm, and the interface trap density ∼1×1012 cm−2 eV−1. The leakage current behavior was consistent with the Poole-Frenkel mechanism of conduction.